Neuroendocrine carcinoma of the breast with hyperprolactinemia: report of two cases and a minireview

Neuroendocrine carcinoma of the breast (NECB) is a rare type of breast cancer. The clinical features and morphology between NECB and other subtypes of breast cancer are indistinguishable. Currently, the diagnosis of NECB mainly relies on immunohistochemical markers including chromogranin and synaptophysin. It is urgent to find new diagnostic markers for NECB. Some evidence suggests a link between high prolactin level and breast cancer development, however, it is unclear whether NECB may be associated with hyperprolactinemia. Here we report two cases of primary NECB with hyperprolactinemia. One patient had a history of mental disorder, while the other experienced pregnancy. Metastatic and associated tumors were not found in both cases, and postoperative studies showed one case was hormone-receptor-dependent, but the other was hormone-receptor-independent. The cases presented here suggest hyperprolactinemia may contribute to NECB development.